There are a variety of commercial systems which are capable of detecting an alarm condition. For example, residential smoke detectors are in wide use and in response to detection of smoke and/or heat produce a piercing audible alarm sound to warn residents of the presence of a fire. Also, there are residential and industrial security systems which will detect fires, unauthorized entry and other types of alarm conditions. The systems may produce an audible sound in the local vicinity of the alarm condition, or may send a signal to a remote location, for example through a dedicated line, a radio link, or a telephone line.
With respect to the transmission of signals to a remote location, the dedicated line is prohibitively expensive in most applications. Further, the radio transmitter and receiver or the telephone dialing circuitry are frequently rather complex, and are thus typically found only in relatively complex units. Therefore, although these units have been generally adequate for their intended purposes, they have not been satisfactory in all respects
It is therefore an object of the present invention to provide an arrangement which is capable of automatically dialing a telephone number in response to detection of an alarm condition, but which is relatively simple and inexpensive and is thus suitable for use in almost any application at low expense.
A further object is to provide such a unit in which a sensor, the dialer and the telephone connection arrangement are all provided within a single housing.